Re: C-x v i bug

From:

Dan Nicolaescu

Subject:

Re: C-x v i bug

Date:

Fri, 18 Dec 2009 09:40:59 -0800 (PST)

Matt Mackall <address@hidden> writes:
> On Fri, 2009-12-18 at 07:54 -0800, Dan Nicolaescu wrote:
> > Martin Geisler <address@hidden> writes:
> >
> > > Dan Nicolaescu <address@hidden> writes:
> > >
> > > > Let's first talk about the original problem that started this
> > > > discussion.
> > > >
> > > > When a file in a directory that is under mercurial control is opened
> > > > in emacs, emacs runs "hg status FILE" so that it knows if it's
> > > > registered or not, if it's modified, etc.
> > > >
> > > > Any user settings in .hgrc should be irrelevant to the above. Right?
> > >
> > > Right. Many people use the color extension to get better feedback from
> > > 'hg status', but if Emacs sets TERM=dumb, then the extension will
> > > disable itself. I'm just mentioning color to say that there are useful
> > > extensions out there that modify even basic commands like 'hg status'.
> > >
> > > > It's desirable that this is as fast as possible, so processing
.hgrc,
> > > > initializing plugins will just waste time.
> > > > After that emacs will want to know the version number for the file,
for that
> > > > it runs "hg log -l1 FILE", and parse it from the output.
> > > > Any user settings in .hgrc should be irrelevant for this command.
Right?
> > >
> > > Right, and it's even quite important that you disable localization
(run
> > > hg with LANGUAGE=C in the environment). Otherwise you'll end up
parsing:
> > >
> > > % hg log -l1 README
> > > ændring: 9586:a41f2840f9c6
> > > bruger: Lee Cantey <address@hidden>
> > > dato: Tue Oct 13 12:27:50 2009 -0700
> > > uddrag: README: revert accidental commit
> > >
> > > The user could also very well have installed a different default style
> > > by setting ui.style. On the command line it's done line this:
> >
> > Thank you, this was very useful in taking care of some issues in emacs.
> >
> > > % hg log -l1 README --style=compact
> > > 9586 a41f2840f9c6 2009-10-13 12:27 -0700 lcantey
> > > README: revert accidental commit
> > >
> > > > [too bad that the status and version number are not available from a
> > > > single command...]
> > >
> > > Well, you know, files don't really have a version number with modern
> > > version control systems. The entire tree has a version number... You
can
> > > of course ask about when a file was last touched, but I think that
> > > information is getting more and more irrelevant these days.
> >
> > In emacs the generic Version Control layer needs a version number in some
case.
> > Here's an example from a bug report:
> >
> > cd /tmp
> > mkdir hgtest2
> > cd hgtest2
> > hg init
> > echo foo > foo.txt
> > hg add foo.txt
> > hg commit -m "Added foo.txt"
> > hg branch bar
> > echo bar > foo.txt
> > hg commit -m "Changed foo to bar"
> > hg update -r default
> > echo frobozz > frobozz.txt
> > hg add frobozz.txt
> > hg commit -m "Added frobozz.txt"
> >
> >
> > now open the file mkdir /tmp/hgtest2/foo.txt and ask to see the
> > annotated version, emacs does that by running
> >
> > hg annotate -r REVISION foo.txt
> >
> > How can REVISION be obtained in this case?
> > It should be "0", but
> > hg log -l1 foo.txt
> > does not show that...
>
> Version numbers are not per-file in Mercurial. The number you should use
> is the global number (or numbers!) reported by hg parents. This revision
> is also known as '.', eg 'hg annotate -r . foo.txt'.
. is not usable in all cases. For the example above:
hg log -r . foo.txt
does not work, it does not show anything.
But "hg parents foo.txt" parse VERSION from there
hg log -r VERSION foo.txt
works.
So it seems that getting the result of hg parents is TRTD.
> You're probably thinking "but I actually want to report the last
> changeset this file was touched in to be more like CVS".
Nope, not at all. Nothing is trying to be like CVS here.
> As a side note, if you want history relative to the working directory
> (and not just all of history), you'll want the -f flag to log.
What's the more useful version that gives the user a better idea what
happened to the file in question?